Thanks Hokusai. I'm not a printer (clearly - what, no Photoshop?) and will be happy to let the printer worry about it, but I remain curious and wish to learn as much as possible so that when I do talk to a printer I can take better advantage of his/her skills in order to achieve the output I want. As for raster vs vector, I am aware of the difference (at least in theory) and for the piece I am currently working on I will likely want to use a combination of a photo and text overlay. The text will need to be "wrapped around" the object that appears in the photo.
In any case, I figured I'd invest in learning Photo to start with.
I'm at the bottom of what looks to be a steep learning curve, and will be happy to take a look at any resources, online or otherwise, that you may wish to recommend. Thanks again.